The subject matter described herein relates generally to methods and systems for assembling a gearbox handling assembly for use in a wind turbine.
At least some known wind turbine towers include a nacelle fixed atop a tower. The nacelle includes a rotor assembly coupled to a gearbox and to a generator through a rotor shaft. In known rotor assemblies, a plurality of blades extend from a rotor. The blades are oriented such that wind passing over the blades turns the rotor and rotates the shaft, thereby driving the generator to generate electricity.
Because many known wind turbines provide electrical power to utility grids, at least some wind turbines have larger components (e.g., rotors in excess of thirty-meters in diameter) that facilitate supplying greater quantities of electrical power. However, the larger components are often subjected to increased loads (e.g., asymmetric loads) that result from wind shears, yaw misalignment, and/or turbulence, and the increased loads have been known to contribute to significant fatigue cycles on the gearbox assembly and/or other components of the wind turbine.
At least some known wind turbines include an electric generator and a gearbox each positioned within the nacelle. The electric generator is coupled to the gearbox with a high speed shaft. At least some known gearbox assemblies facilitate transferring rotational energy from a low speed rotor shaft to a high speed shaft that rotatably drives the generator to facilitate producing electrical power. Over time, the bearings which support the high speed shaft may become worn. As the bearings become worn, the gearbox assembly becomes less effective in transferring rotational energy to the generator. In some cases, the bearings fail which results in damage to the bearing bores. In at least some known wind turbines, the repair of the gearbox requires the entire nacelle, gearbox, and rotor to be removed from the wind turbine prior to removing the gearbox and repairing and/or replacing the damaged gearbox. In some wind turbines, the blades are between 60 and 100 meters in length, and as such, repairing worn or damaged gearboxes can be costly and time-consuming.
Accordingly, it is desirable to provide a system and method for removing and/or replacing the gearbox uptower without removing the rotor and/or the rotor shaft from the wind turbine.